Frost dates for 46563Plymouth, IN
The average last spring frost in Plymouth is April 25 and the average first fall frost is October 21, giving a typical growing season of about 178 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 25
- Average first fall frost
- Oct 21
- Growing season
- 178 days
Safer after May 13 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 173 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 22 · May 6 · May 23 | Sep 27 · Oct 9 · Oct 24 | 154 days | 100% |
| Frost / freeze (32°F) | Apr 12 · Apr 25 · May 13 | Oct 5 · Oct 21 · Nov 3 | 178 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 14 · Apr 30 | Oct 19 · Nov 1 · Nov 15 | 200 days | 100% |
Planting calendar for Plymouth
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 25 – May 31 |
| Tomatoes | Transplant outdoors | May 11 – Jul 1 |
| Peppers | Start seeds indoors | Mar 25 – Apr 25 |
| Peppers | Transplant outdoors | May 25 – Jun 25 |
| Eggplant | Start seeds indoors | Apr 11 – May 10 |
| Eggplant | Transplant outdoors | May 25 – Jun 25 |
| Cucumbers | Sow outdoors | May 25 – Jul 11 |
| Summer squash | Sow outdoors | May 11 – Jun 25 |
| Winter squash & pumpkins | Sow outdoors | May 25 – Jun 25 |
| Snap beans | Sow outdoors | May 11 – Aug 3 |
| Sweet corn | Sow outdoors | May 11 – Jul 1 |
| Watermelon & cantaloupe | Sow outdoors | May 25 – Jun 25 |
| Okra | Sow outdoors | May 18 – Jun 10 |
| Peas | Sow outdoors (spring) | Mar 25 – May 10 |
| Potatoes | Plant outdoors (spring) | Mar 25 – May 25 |
| Onions | Start seeds indoors (spring) | Feb 11 – Mar 10 |
| Onions | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (spring) | Mar 7 – Apr 10 |
| Broccoli | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (fall) | Jun 21 – Jul 1 |
| Broccoli | Transplant outdoors (fall) | Jul 21 – Aug 1 |
| Cabbage | Start seeds indoors (spring) | Feb 25 – Mar 25 |
| Cabbage | Transplant outdoors (spring) | Mar 25 – Apr 25 |
| Cabbage | Start seeds indoors (fall) | Jun 11 – Jul 11 |
| Cabbage | Transplant outdoors (fall) | Jul 11 – Aug 11 |
| Leaf lettuce | Sow outdoors (spring) | Mar 25 – Jun 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 11 – Aug 27 |
| Spinach | Sow outdoors (spring) | Mar 18 – May 1 |
| Spinach | Sow outdoors (fall) | Jul 28 – Sep 1 |
| Radishes | Sow outdoors (spring) | Mar 25 – May 15 |
| Radishes | Sow outdoors (fall) | Jul 11 – Sep 11 |
| Kale | Sow outdoors (spring) | Apr 11 – May 1 |
| Kale | Sow outdoors (fall) | Jul 4 – Aug 11 |
| Carrots | Sow outdoors (spring) | Apr 25 – Jun 10 |
| Carrots | Sow outdoors (fall) | Jun 11 – Jul 27 |
| Garlic | Plant outdoors (fall) | Oct 11 – Nov 11 |
Where these dates come from
ZIP code 46563 is matched to the NOAA station Plymouth, IN, 3.2 km away, at 815 ft elevation (41 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Plymouth, IN (used) | 815 ft | Apr 25 | Oct 21 |
| Lakeville, IN | 841 ft | May 1 | Oct 13 |
| Knox Wwtp, IN | 690 ft | Apr 26 | Oct 19 |
| Rochester, IN | 760 ft | Apr 23 | Oct 21 |
Frost dates near Plymouth
- Tyner, IN 46572 · last Apr 25, first Oct 21
- Lapaz, IN 46537 · last May 1, first Oct 13
- Donaldson, IN 46513 · last Apr 25, first Oct 21
- Bremen, IN 46506 · last May 1, first Oct 13
- Argos, IN 46501 · last Apr 25, first Oct 21
- Bourbon, IN 46504 · last Apr 25, first Oct 21
- Culver, IN 46511 · last Apr 25, first Oct 21
- Grovertown, IN 46531 · last Apr 25, first Oct 21
Frequently asked questions
- When is the last frost in Plymouth, IN?
- For ZIP code 46563, the average last spring frost (32°F) is April 25, based on NOAA 1991-2020 climate normals for the Plymouth, IN weather station. There is a 1-in-10 chance of a frost after May 13.
- When is the first frost in Plymouth, IN?
- The average first fall frost (32°F) is October 21. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 46563?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 178 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.